It is very old to provide multiple port fluid control devices for selectively connecting together different combinations of a plurality of ports. One common form is a three-way valve which has one inlet port and two outlet ports. The inlet port is selectively connected to one or the other of the two outlet ports depending upon the position of the valve mechanism.
Many of such prior art devices are, however, relatively complicated. In some cases, they employ valve seats which must be very carefully machined. In many cases, interlocking parts are employed, all of which must be fitted together very carefully.